public class DriverText {
    public static void main(String[] args) {
        Driver d=new Driver();
        d.name="老马";
        Car c=new Car(5,6);
        d.steer(c);
        Aircraft a=new Aircraft(1,10000);
        d.steer(a);
        Tank t=new Tank(500,60);
        d.steer(t);
        Tractor tr=new Tractor(3000,600);
        d.steer(tr);
        Steamer s=new Steamer(6000,90000,5000);
        d.steer(s);
    }
}
